Download Fact Sheet: Pegasys

FACTSHEET
Pegasys
Summary
Pegasys is the name of a long-lasting form of interferon-alfa-2a. It is used for the treatment
of hepatitis C virus (HCV) infection. Pegasys is taken by injection once weekly. Side effects
include fever, headache, tiredness and sometimes depression.
What is Pegasys?
Pegasys is the brand name of a long-lasting form
of alpha interferon called peginterferon
(pegylated interferon-alfa-2a).
How does Pegasys work?
Alpha interferon is the name of a chemical
messenger, or cytokine, made by cells in your
body. This cytokine has at least two important
roles:
• It protects your cells from infection by HCV.
• It helps your immune system fight HCV.
The “peg” in peginterferon stands for
polyethylene glycol. When peg is attached to
interferon, it provides a protective barrier that
shields the interferon from being broken down,
thus prolonging the time it remains in the blood.
Regular interferon needs to be injected at least
three times weekly. Pegasys only has to be
injected once a week. Pegasys also appears to
be stronger than regular interferon.
How do people with HIV use Pegasys?
Your doctor has recommended Pegasys for you
because you have HCV infection. He or she has
decided that you require treatment to help
reduce liver damage caused by HCV.
For more information about HCV and the liver,
see the CATIE in-depth Fact Sheet on hepatitis C
available at: www.catie.ca/facts.nsf.
Because Pegasys would be destroyed in your
stomach if it were swallowed, it must be injected
under the skin, once weekly. Speak to your clinic
nurse, who can teach you how to inject yourself
or may be able to inject the drug for you—
whichever method is best for you. This drug is
usually taken at bedtime, for up to one year. To
make Pegasys more effective at treating HCV,
your doctor will also prescribe another drug
called ribavirin.
To ensure that combination therapy with Pegasys
and ribavirin is working, your doctor will have
your blood tested on a regular basis.
What is ribavirin and how is it used?
Ribavirin is a type of drug called a “nuke” (or
nucleoside analogue). When taken by itself,
ribavirin is a weak drug. However, when taken
together with Pegasys, the combination is
powerful. People with HIV who take Pegasys
usually also take ribavirin at doses ranging
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between 800 and 1,200 mg/day, depending on
your weight. Ribavirin is taken orally with meals.
Injecting Pegasys
Your nurse will teach you how to inject Pegasys
under the skin. As well, the manufacturer,
Hoffman-La Roche, has prepared booklets and
brochures to help you with self-injecting. Ask
your nurse or doctor for these materials. The
best places on the body to inject Pegasys include
the following:
• upper leg or thigh;
• outer part of the upper arm;
• abdomen (but not the belly button or waist).
Do not inject Pegasys into the same place all the
time; you should change injection sites in a
regular pattern. Some clinics may let you come
in once a week so the clinic nurse can inject you,
if you prefer.
Warnings
Although potent, combination therapy for HCV
with Pegasys and ribavirin is not for everyone
with HCV.
1. Mental health
We are about to describe a series of problems
that may occur in some people who use Pegasys
and ribavirin. Once you have started combination
therapy for HCV, if you notice any of these
problems, talk to your doctor right away:
• you become easily upset or angry;
• you have unexpected feelings of sadness;
• you feel hopeless;
• you have thoughts about harming yourself or
others (such as thinking about starting to use
street drugs again if you were using in the
past);
• you have thoughts about suicide.
2. Lactic acidosis
Lactic acidosis is the name given to a condition
where high levels of lactic acid build up in the
blood. It is a rare side effect that may be
associated with the use of nukes used to treat
HIV, such as AZT, ddI, ddC, d4T and 3TC. It may
also occur in people with HIV who use the nuke
ribavirin, particularly if they also use the nukes
ddI (didanosine, Videx, Videx EC) and/or d4T
(stavudine, Zerit). These drugs damage the
energy-producing parts, or power plant, of a cell.
When a cell can’t produce enough power, it
begins to malfunction and can die. The following
signs/symptoms can develop when a person has
lactic acidosis:
• unexpected tiredness;
• nausea and/or vomiting;
• abdominal pain;
• shortness of breath.
If you have these symptoms, talk to your doctor
right away.
Blood tests can help your doctor determine
whether you have lactic acidosis. The following
levels may indicate this problem:
• lactate levels of 5 mmol/L or greater;
• bicarbonate levels of 20 mmol/L or lower.
3. Pregnancy
If you are pregnant or think that you may be
pregnant and you are taking Pegasys and
ribavirin, talk to your doctor right away. These
drugs should not be used by the following people:
• pregnant women;
• women who may become pregnant and their
male partners.
This is because the combination of these drugs
can severely damage the fetus. Pregnancy should
not be planned while you or your partner are on
this therapy. If you are planning to have a baby,
you should wait up to six months after therapy
has been stopped. Ribavirin can also be toxic to
sperm.
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4. Heart, stroke and blood problems
Some people who have used Pegasys have
developed heart problems, including low blood
pressure, rapid heart beats and chest pain.
Ribavirin in combination with peginterferon can
cause anaemia (a drop in the number of red blood
cells). Pegasys can also lower levels of white
blood cells, including a group called neutrophils,
increasing your risk of developing infections. As
well, this drug can reduce levels of platelets in
your blood. Because platelets are needed to help
your blood clot, having less-than-normal levels
of platelets increases your risk of bleeding. Tell
your doctor right away if you have any of these
problems.
Some people who have used Pegasys have
developed bleeding in the brain (a stroke). These
people had few or no risk factors for stroke and
they have happened in young people. Signs and
symptoms of a stroke include the following:
• sudden numbness or weakness of face, arm,
or leg, especially on one side of the body;
• sudden confusion or trouble speaking or
understanding speech;
• sudden trouble seeing in one or both eyes;
• sudden trouble walking, dizziness, or loss of
balance or coordination;
• sudden severe headache with no known cause.
If you have any of these go to your nearest
emergency department immediately.
5. Infections
A temporary fever is a normal reaction to
interferon treatment. However, a high fever or
a fever that does not go away needs to be
investigated to ensure that there is not some
other cause, such as an infection. If you have a
high or persistent fever while using interferon,
tell your nurse and doctor.
6. Skin rash
Rash can occur in people using Pegasys. In rare
cases the rash may be serious. If you have a
severe rash with blisters, fever, or sores in your
mouth, nose or eyes (or your eyes become red)
contact your doctor right away.
7. Changes in vision
Some people who use Pegasys may develop
blurred vision or other problems seeing. If this
happens, tell your doctor right away.
Side effects
1. Common side effects of interferon that
occurred in clinical trials were those belonging
to a flu-like syndrome as follows:
• unexpected tiredness;
• headache;
• fever;
• muscle and/or bone pain;
• chills.
These side effects tend to appear between six
and eight hours after injection with Pegasys.
Some doctors recommend that their patients premedicate, that is, take pain-relievers such as
ibuprofen (Advil, Motrin) before injecting
Pegasys, to prevent or reduce these side effects.
Taking Pegasys at bedtime may also be helpful.
Drinking plenty of healthful fluid—water, juices,
herbal teas—that do not contain caffeine is useful
when taking Pegasys therapy. Make sure to get
a balance of rest and at least some mild exercise.
Other side effects of Pegasys include the
following:
• coughing;
• reduced appetite;
• shortness of breath;
• minor, temporary hair loss;
• dry and itchy skin;
• psoriasis.
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2. Interferon and the brain
Pegasys can temporarily affect the brain and
some people also develop the following
symptoms:
• difficulty falling asleep;
Dosage
The dose of Pegasys normally used is 180 micrograms
(mcg), once a week. This is written as
180 µg/week. The drug is injected under the skin
at bedtime. Keep Pegasys in your refrigerator.
• problems thinking clearly;
The dose of ribavirin used with Pegasys will be
adjusted depending on your weight. Ribavirin is
taken orally with meals.
• depression.
Availability
• reduced ability to concentrate;
• increased feelings of irritability;
The depression may require treatment while you
are taking Pegasys. If you have had depression
before taking Pegasys let your doctor know so
that together you can come up with options to
prevent or treat this problem for managing
depression. The dose of Pegasys may be reduced
in some cases, depending on the degree of
depression.
3. Other side effects
The combination of Pegasys and ribavirin will
temporarily affect your bone marrow and can
cause a drop in white and red blood cells. Regular
blood tests are important to monitor this
problem. The dose of ribavirin may be reduced
if your blood counts fall too low. Your thyroid
gland and the hormones it produces will also be
temporarily affected by this treatment. All in
all, regular visits to your doctor for checkups and
blood tests are very important while you are
taking Pegasys and ribavirin.
Always tell your doctor and nurse about your side
effects.
Drug interactions
Both Pegasys and ribavirin can temporarily
weaken the bone marrow. Use of the anti-HIV
drug AZT (zidovudine, Retrovir and also found in
the combination pills Combivir and Trizivir) may
make this worse.
Ribavirin may weaken the activity of the
anti-blood-clotting drug warfarin (Coumadin).
In Canada, Pegasys and ribavirin are approved
for treating HCV. Conditions for subsidized access
to these medicines is different in each province
and territory—speak to your infectious disease
or liver specialist to find out more. CATIE’s online
module Federal, Provincial and Territorial
Drug Access Programs (on CATIE’s website
at www.catie.ca/eng/Publications/drugaccess/
drugaccessIndex.shtml) also contains information
about Canadian drug coverage.
Credits
Author: Sean R. Hosein
Revised 2009
References
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coinfected with HIV and hepatitis C virus: 2007 updated
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Levy DE. Whence interferon? Variety in the production of
interferon in response to viral infection. Journal of Experimental
Medicine 2002;195(4):F15–F18.
Zeuzem S, Feinman SV, Rasenack J, et al. Peginterferon alfa-2a
in patients with chronic hepatitis C. New England Journal of
Medicine 2000; 343(23):1666–1672.
Heathcote EJ, Shiffman ML, Cooksley WG, et al. Peginterferon
alfa-2a in patients with chronic hepatitis C and cirrhosis. New
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Perry CM and Jarvis B. Peginterferon-alfa-2a (40kD): a review
of its use in the management of chronic hepatitis C. Drugs 2001;
61(15):2263–2288.
Patten SB. Psychiatric side effects of interferon treatment.
Current Drug Safety 2006 May;1(2):143–50.
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ribavirin in the combination treatment of chronic HCV infection.
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ribavirin. Lancet 2001;357;1802–1803.
Salmon-Céron D, Chauvelot-Moachon L, Abad S, et al.
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Guyader D, Poisignon Y, Cano Y and Saout L. Fatal lactic acidosis
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for chronic hepatitis C. Journal of Hepatology 2002;37:289–292.
Bini EJ, Mehandru S. Incidence of thyroid dysfunction during
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Medicine 2004 Nov 22;164(21):2371–2376.
Carella C, Maziotti G, Morisco F, et al. The addition of ribavirin
to interferon-alpha therapy in patients with patients with
hepatitis C virus-related chronic hepatitis does not modify the
thyroid autoantibody pattern, but increases the risk of
developing hypothyroidism. European Journal of Endocrinology
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Narayana K, D’Souza UJA and Rao KPS. Ribavirin-induced sperm
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